What Is a Credit Spread (and Why It Changes)?

Every corporate bond yields more than a government bond of the same maturity. The gap between the two is called the credit spread. Understanding what the credit spread represents, what causes it to change, and what typical spreads look like across credit rating categories gives you a practical tool for evaluating whether a bond’s yield compensates you adequately for the risk you are taking. This article covers the mechanics, the Indian context, and how to use spread data in practice.

What is a credit spread?

A credit spread is the difference in yield between a corporate bond and a comparable government bond — “comparable” meaning similar maturity and currency. The government bond serves as the “risk-free” baseline, and the corporate bond’s yield premium above that baseline is the credit spread.

Formula: Credit Spread = Corporate Bond YTM − Benchmark G-Sec YTM

Example: A 5-year AAA-rated corporate NCD yields 7.7%. The 5-year G-Sec yields 7.0%. The credit spread is 70 basis points (0.70%). This 70 bps is the market’s price for the additional risks of lending to this corporate entity rather than to the Government of India.

Spreads are expressed in basis points (bps), where 1 basis point = 0.01%. So 100 bps = 1%.

What does the spread compensate for?

The credit spread is not a single, monolithic payment for one risk. It bundles together compensation for several factors:

Credit risk: The primary component. The possibility that the issuer will fail to pay some or all of the promised cash flows. Higher credit risk demands a larger spread. A BBB-rated issuer faces meaningfully higher default probability than a AAA-rated issuer, and the spread reflects that.

Liquidity risk: Corporate bonds, particularly those not in benchmark indices, trade far less frequently than G-Secs. If you need to sell before maturity, you may face a wide bid-ask spread and may not find a willing buyer at the “fair” price. Investors demand extra yield to hold less liquid instruments. This liquidity premium can be substantial for smaller, unlisted, or lower-rated NCDs.

Information asymmetry: Analysing a corporate issuer’s financial health requires effort that G-Sec analysis does not. Investors charge a premium for this analytical burden and for the risk that they are working with incomplete information.

Structural complexity: Many corporate bonds have call options, step-up clauses, or covenant structures that introduce optionality and uncertainty. Investors price in this complexity through the spread.

Typical credit spreads by rating category in India

These are approximate ranges as of mid-2026. Spreads vary by sector (NBFC bonds typically command higher spreads than comparable PSU bonds for the same rating), instrument structure, issuer-specific factors, and prevailing market conditions. The ranges above should be treated as orientation points, not precise benchmarks.

Why spreads change over time

Credit spreads are not fixed. They move continuously based on macroeconomic conditions, monetary policy, and issuer-specific events. Understanding what drives spread movements helps in interpreting the market signal they carry.

Economic cycle: During expansions, default rates fall, corporate cash flows are healthy, and investors feel comfortable reaching for yield. Spreads compress (narrow) as demand for corporate bonds rises. During contractions or recessions, the opposite happens: investors grow cautious, demand falls, and spreads widen as investors require larger compensation for the higher perceived risk of default.

Liquidity conditions: When the banking system is flush with liquidity (as during periods of RBI accommodation), excess funds flow into corporate bond markets. Spreads compress. When liquidity tightens — as it does when the RBI is in a tightening cycle or when there is global stress — the flow reverses and spreads widen.

Flight to quality: During periods of market stress (a major credit event, a global shock, or a banking crisis), investors rapidly move from corporate bonds into government bonds regardless of the specific credit quality of any individual issuer. This simultaneous selling of corporate bonds and buying of G-Secs causes spreads to widen sharply and quickly. This is called a “flight to quality” or “flight to safety.”

Rating actions: A downgrade from AAA to AA+ will typically widen the spread on that particular issuer’s bonds as the market reprices the higher perceived risk. An upgrade has the opposite effect. Rating actions can be anticipated by the market before they are formally announced, so you may see spread widening before the official downgrade.

Sector stress: When problems emerge in a specific sector — for example, the NBFC liquidity crisis of 2018-19 — spreads on all bonds in that sector widen, even for issuers not directly affected. Contagion is a real phenomenon in credit markets.

Spread compression vs spread widening

Spread compression (spreads narrowing) means corporate bonds are becoming relatively more expensive compared to G-Secs. From a new investor’s perspective, this means you are receiving less yield premium for the credit risk you are taking. Markets describe this as “priced for perfection” when spreads are very tight: there is little cushion if conditions deteriorate.

Spread widening means corporate bonds are getting cheaper relative to G-Secs. From a new investor’s perspective, this means more yield for the same credit quality. For an existing holder, spread widening means the market price of your bond has fallen (since the bond now needs to offer more yield, which means a lower price). This is why credit events can cause significant mark-to-market losses for bond fund investors even if the underlying bonds have not defaulted.

Using spread data to evaluate bonds

When you see a bond with a headline yield, the first question should be: what is the spread over the comparable G-Sec, and is that spread reasonable given the rating, sector, and issuer?

Step 1 — Find the comparable G-Sec yield. Match the maturity of the corporate bond to the nearest G-Sec benchmark. If the corporate bond matures in 4 years, use the 4-year or 5-year G-Sec yield as the reference. The RetailBonds screener shows G-Sec benchmark yields alongside corporate bond yields to simplify this.

Step 2 — Calculate the spread. Subtract the G-Sec yield from the corporate bond YTM. Express this in basis points.

Step 3 — Compare to typical spreads for the rating. Is 70 bps over G-Sec reasonable for a AAA-rated issuer? Yes, it is within the typical range. Is 70 bps over G-Sec reasonable for an A-rated issuer? No — it is far too low; either the rating is being evaluated too generously, or the bond lacks liquidity and the quoted yield may not be achievable.

Step 4 — Compare within the sector. If you are evaluating an NBFC NCD, compare its spread to other NBFCs of similar rating, not to PSU bonds or banks. Sector peers are the most relevant benchmarks.

Step 5 — Look at spread history. If a bond’s spread has widened recently relative to its own history and peers, it is worth investigating why. Has there been a rating watch? A management change? An increase in leverage?

Spread and the “carry” concept

In fixed income, “carry” refers to the income you earn from holding a position. For a corporate bond, the carry above the risk-free rate is the spread. If you hold a bond with a 100 bps spread over G-Secs, and spreads remain constant, you earn that 100 bps per year as excess return over a G-Sec.

The risk is that spreads widen against you: your bond falls in price even if the issuer hasn’t defaulted. If you hold to maturity and the issuer does not default, you still receive your contracted cash flows and the spread income. If you need to sell before maturity, you are exposed to mark-to-market losses during spread-widening episodes.